Shell thin, inflated, subventricose,brittle, elongate-ovate, anterior end rounded, posterior end attenuated, narrow, posteriorly gaping: ventricose in the middle. Umbonal reflection simple, closely adhering to the shell. Sculptured with strong radial and concentric ridges, anteriorly strongest and spiny at the intersections. Irregularly oval protoplax with a shallow central groove. Small, thin, apophysis in each valve. Pallial sinus deep. Colour: unicolour white; periostracum thin, pale brown.